All-optical format and bit rate transparent data networks generally do not need to terminate and read bits in the signals that they propagate. This allows a considerable savings, both financially and in terms of device complexity, relative to OEO networks with their complex OEO receivers. This effect is especially seen as regards high bit rate networks and traffic, where due to bit rate OEO dependence, dedicated high speed receivers are required. Besides client traffic, data networks also transmit and receive maintenance signals of various types. Advanced all-optical networks utilize “optical alphabets” to implement this signaling, and thus do not need to terminate bits and decode information encoded in them. Nonetheless, all-optical networks may still need to read information by terminating bits from non-client traffic, such as maintenance signals. This occurs when all-optical sub-networks or network nodes are used within larger OEO networks, or are desired to be compatible with such networks. In such contexts, it is inefficient to provide each all-optical network element with the full cadre of OEO receivers simply to decode maintenance signal traffic. What is needed is an efficient means of enabling optical data networks with the ability to generate and detect maintenance signals in bit encoded formats.